Flip electronic devices, such as notebook computer, mobile phone or the like, usually have a screen connected with a keyboard via a hinge to provide a required torsional force when the screen is unfolded against the keyboard. The common flip electronic device often has a hinge pivotally coupled with a base and an upper lid thereof to make them foldable and unfoldable. For instance, R.O.C. patent No. M388822 discloses a turnable double-pin hinge with a first pin fastened to a screen bracket and a second pin fastened to a base bracket. The first pin can be swiveled about the second pin to change the position of the first pin upwards or rearwards, thereby drive the screen bracket upwards or rearwards to prevent interference between the screen housing and base housing during unfolding. It also has a track panel and a control member to harness movements so that the screen bracket can be swiveled at an angle equal to the sum of the swivel angles of the first pin and second pin. Namely the swivel angle of the screen is formed by combining the turning angles of the first pin and second pin. However, the aforesaid flip electronic device has to swivel the screen and base at an included angle greater than 90 degrees to provide a comfortable visual angle for users to see the information displayed on the display device such as the screen.
In order to save use space, R.O.C. patent No. M413776 discloses a band type double-pin hinge. It includes a pin sleeve and a first swivel member and a second swivel member located in the pin sleeve. The pin sleeve has a coupling plate and a first coupling portion and a second coupling portion located on the coupling plate. The first coupling portion and second coupling portion have respectively a first pin passage and a second pin passage to hold respectively the first swivel member and second swivel member. The first coupling portion has an edge at one side of the coupling pate formed a first notch communicating with the first pin passage, and the second coupling portion has another edge at another side of the coupling plate formed a second notch communicating with the second pin passage. The double-pin hinge thus formed can be swiveled sequentially at a greater angle, and also can be unfolded lightly and folded at a greater force. It also allows the upper lid to be flipped 360 degrees to fold over the base. Although it saves use space, the entire electronic device has to be taken up to flip the upper lid for 360 degrees, then be rested on a flat surface. It still leaves a lot to be desired in terms of usability.
From user's perspective, usability can be greatly enhanced if the hinge is constructed to enable the screen to be flipped directly from the tabletop not greater than 90 degrees without holding the entire electronic device while the screen can be seen by users at the front side.